Wisconsin Gov. Scott Walker, one of three Republican governors whose presidential ambitions have been tainted by allegations of wrongdoing, was at the heart of a “criminal scheme” to violate election laws, according to a prosecutor's documents released Thursday.

No charges have been filed in the case, which has been investigated by special prosecutor Francis Schmitz.

According to the documents, Walker, who is running for reelection, and top staffers were involved in coordinating their efforts during the state’s recall elections with “a number of national groups and prominent figures,” such as Karl Rove, the GOP’s long-standing eminence grise, not to mention the Democrats' bete noire.

Walker called the prosecutor's statement "categorically false."

“This is nothing more than a partisan investigation with no basis in state law.... Now my Democratic opponents will use these false accusations to distract from the issues important to the voters of Wisconsin,” he said in a statement.

Because of court cases, it has been widely known in Wisconsin that there was an ongoing investigation -- known as a John Doe probe -- into recall campaigns in 2011 and 2012, focusing on allegations of illegal coordination among the governor’s staff and conservative groups. But the documents released Thursday allege that Walker had a more personal and central role.

“The scope of the criminal scheme under investigation is expansive,” Schmitz wrote in the Dec. 9 court filing, objecting to an attempt by Walker's campaign and other conservative groups to quash subpoenas. “It includes criminal violations of multiple elections laws,” including filing false campaign finance reports, Schmitz wrote.

The court papers were released as part of a civil suit involving various organizations, including the Wisconsin Club for Growth, which argued that prosecutors had violated its 1st Amendment rights. A federal judge had ruled in the group's favor, and a federal appeals judge is reviewing a temporary injunction that barred further investigation of the allegedly illegal coordination.

The legal fight and the accusations against Walker are expected to factor in this year’s gubernatorial race, in which Democrat Mary Burke, the likely candidate, is seeking to unseat Walker.

“It is completely unprecedented in Wisconsin for the governor to have a direct role in this kind of expansive criminal scheme,” said Melissa Baldauff, communications director for the state Democratic Party.

If Walker wins reelection, he might be able to seek a spot on the GOP national ticket in the 2016 presidential race.

In the last presidential campaign, Republicans were looking at three powerful and well-liked governors as potential candidates down the road.

One, New Jersey’s Chris Christie, has been embroiled in a scandal over halted traffic on the George Washington Bridge, among other allegations.

The third was Walker, who entered the national spotlight for pushing a law limiting collective bargaining rights for most public employees as well as spending cuts in Medicaid and education. Those battles led to a rare legislative walkout by Democratic state senators, who went into hiding temporarily to deprive the chamber of a quorum. There were also angry demonstrations at the Capitol in Madison.

The furor eventually led to recall elections as Democrats, pushed by their union allies, fought to throw Walker and his legislative allies out of office. In 2012, Walker prevailed and became the first governor to win a recall election.

But the victory came at a price, prosecutors allege. They say Walker reached out to like-minded national conservative groups in violation of election law. The defendants say their actions were legal.

“The investigation focuses on a wide-ranging scheme to coordinate activities of several organizations with various candidate committees to thwart attempts to recall Wisconsin Senate and gubernatorial candidates,” prosecutor Schmitz said, according to the court papers.

“That coordination included a nationwide effort to raise undisclosed funds for an organization which then funded the activities of other organizations supporting or opposing candidates subject to recall. The subpoenas are necessarily broad in an effort to collect additional evidence because the coordination activities were extensive and involving at least a dozen separate organizations.”

The investigation began in 2012 as Walker was facing recall, but it has been on hold since May, when a federal judge temporarily halted it while the issues were being litigated.

Walker is not a party to the civil suit, according to his campaign, and thus has no control over which documents are released.

“Two judges have rejected the characterizations disclosed in those documents,” campaign spokeswoman Alleigh Marre said in a statement emailed to reporters, referring to previous rulings favorable to the governor and his team, including political consultant R.J. Johnson.

The newly released court documents cite an email from Walker to Rove on May 4, 2011, in which Walker described Johnson’s importance.

“Bottom-line: R.J. helps keep in place a team that is wildly successful in Wisconsin,” the email says. “We are running 9 recall elections and it will be like 9 congressional markets in every market in the state (and Twin Cities).”